1. Field
Example embodiments relate to resistive random access memory (RRAM) devices and resistive random access memory arrays having the same.
2. Description of the Related Art
Semiconductor memory devices have been actively researched and developed with respect to integration, operation speed and/or driving power. Dynamic random access memory (DRAM), as a representative semiconductor memory device, has high integration and operation speed but is a volatile memory device that loses all stored data when power is off.
A flash memory has lower integration and operation speed than DRAM but is a non-volatile memory device that retains stored data even when power is off. Non-volatile memory devices include magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase-change random access memory (PRAM) and resistance random access memory (RRAM).
RRAM uses a variable resistance material having a resistance that varies at a certain voltage. For example, if a set voltage is applied to the variable resistance material, the resistance of the variable resistance material is reduced so as to be in an on state. If a reset voltage is applied, the resistance of the variable resistance material is increased so as to be in an off state. The variable resistance material of the RRAM may also have various resistance values according to an applied voltage. As such, a relatively high recording density may be realized.